The quality of root canal treatment and periapical status of permanent teeth in Turkish children and teens: a retrospective CBCT study.

OBJECTIVE: This study aimed to assess the quality of root canal fillings and the prevalence of periapical radiolucencies in the permanent teeth of 6-18 year-old Turkish children. METHODS: CBCT images of 150 patients' 235 teeth with a mean age of 16.0 ± 2.06 years were included. Root development stage, quality of root canal filling, the presence and severity of periapical radiolucencies, and their relationship with anatomical structures were recorded. Correlations between the quality of root canal filling, periapical lesion, and lesion size were assessed using regression analyses. RESULTS: A total of 235 teeth (528 root canals) were evaluated. 65.5% of root canals had periapical lesions. Immature roots and mandibular teeth had the highest prevalence and the largest size of periapical radiolucencies (p < 0.05). Overfilling (n = 52), underfilling (n = 93), unfilled (n = 46), inhomogeneously filled (n = 113) root canals and poor coronal restoration (n = 85 teeth) were observed in terms of technical failures of endodontic treatment. The quality of endodontic treatment was associated with the presence of periapical lesion and lesion size (p < 0.05). Teeth with under-filled, overfilled or inhomogeneously filled root canals and poor coronal restoration had a periapical lesion larger than 5 mm (p < 0.05). Immature teeth were most associated with the presence of lesion (OR = 4.07) and the lesion size > 5 mm (OR = 3.71). CONCLUSION: The prevalence of periapical radiolucencies in young permanent teeth showed an increase when the tooth was an incisor, had incomplete root development, or the root filling had technical errors.

Prevalence of Premature Eruption and Agenesis of Premolars in Turkish Children: A Retrospective Study.

OBJECTIVE: To determine the prevalence and distribution of premature eruption and agenesis of premolars in a sample of Turkish children. STUDY DESIGN: A sample of 1715 patients aged 5 to 11 years was selected. Panoramic radiographs were used to assess premature eruption and agenesis of premolars. Developmental stage of erupted premolars was assessed using Demirjian's method and selecting prematurely erupted premolars on the basis of clinical eruption with a root length less than half of their final expected root lengths. Statistical analysis was performed using chi-square test (p <.05). RESULTS: One hundred fifteen (6.7%) of 1715 patients presented at least one premolar agenesis with no significant sex difference (56 boys, 59 girls). Mandibular second premolars were the most absent teeth. Multiple agenesis of premolars (3.4%) was more common than single agenesis (3.3%). A total of 85 (5.0%) patients (51 boys, 34 girls; no significant sex difference) had at least one prematurely erupted premolar, and maxillary first premolars were most commonly affected. Early erupted premolars were in stage D or E based on Demirjian's dental formation scale. CONCLUSIONS: The prevalence of premature eruption and agenesis of premolars in Turkish children were 5.0% and 6.7%, respectively. Both conditions are not uncommon and may highlight the need for early diagnosis to prevent subsequent clinical problems.

Effect of Er,Cr:YSGG Laser on the Prevention of Primary and Permanent Teeth Enamel Demineralization: SEM and EDS Evaluation.

Objective: To evaluate in vitro the effect of the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on resistance of primary and permanent human enamel to demineralization using water cooling and fluoride coapplication as variable parameters. Methods: Enamel specimens were prepared from extracted primary and permanent teeth (n = 225 each). The specimens were separated into 15 subgroups (n = 15/group) based on laser application at three different power settings (0.25, 0.50, and 0.75 W), laser application with and without water cooling, and application of acidulated phosphate fluoride (APF) gel before laser treatment. Morphological changes were assessed with scanning electron microscopy (SEM), and the specimens' chemical contents were determined with energy-dispersive X-ray spectroscopy. Results: In both the primary and permanent teeth, the highest Ca and P content was observed in the noncooled 0.75 W laser group (p < 0.05), irrespective of APF pretreatment (p > 0.05). The Ca and P content for the noncooled APF +0.75 W laser group was lower than that for the APF group and the noncooled 0.75 W laser group. For both dentitions, the F mass content for the APF+laser groups was significantly higher than laser-only groups (p < 0.05). Under SEM, both the primary and permanent enamel exhibited cracks, craters, and surface roughness without water cooling, consistent with increased power output. Conclusions: Er,Cr:YSGG laser application at 0.75 W without water cooling increased enamel resistance to demineralization. Compared with topical APF application, Er,Cr:YSGG laser application barely improved enamel resistance against demineralization, and coapplication did not result in a synergistic effect.

Biomechanical evaluation between orthodontic attachment and three different materials after various surface treatments: A three-dimensional optical profilometry analysis.

OBJECTIVES: To determine the best bonding method of orthodontic attachment among monolithic zirconia, feldspathic porcelain, hybrid porcelain, and the impact of surface-conditioning methods using a three-dimensional optical profilometer after debonding. MATERIALS AND METHODS: 56 feldspathic porcelain, 56 monolithic zirconia, and 56 hybrid porcelain samples were divided into four surface treatment subgroups: (1) hydrofluoric (HF) acid etch + silane, (2) Al2O3 sandblasting + silane, (3) silicoating (SiO2), and (4) diamond bur + silane. The specimens were tested to evaluate shear bond strength (SBS). Residual composite was removed after debonding. Three-dimensional white-light interferometry was used to obtain quantitative measurements on surface roughness. RESULTS: The highest SBS value was found for the HF acid-etched feldspathic porcelain group. The average surface roughness values were significantly higher in all material groups in which diamond bur was applied, while roughening with Cojet provided average surface roughness values closer to the original material surface. CONCLUSIONS: Variations in structures of the materials and roughening techniques affected the SBS and surface roughness findings.

Fracture resistance of simulated immature teeth after internal bleaching procedures.

The aim of this study was to evaluate the fracture resistance of simulated immature teeth after internal bleaching. The teeth were assigned as follows (n = 12/group); Group-1: The pulp chamber was filled with ProRootMTA and bleached intracoronally with sodium perborate mixed with 37% carbamide peroxide gel; Group-2: The pulp chamber was filled with ProRootMTA without bleaching; Group-3: The pulp chamber was filled with Biodentine and bleached intracoronally as Group-1; Group-4: The pulp chamber was filled with Biodentine without bleaching; and Group-5: Teeth received no intervention (control). The specimens were loaded vertically until root fracture occurred. The data were analysed with Kruskal-Wallis and Dunn tests. There was no significant difference between the fracture resistances of the experimental groups (P > 0.05). However, all experimental groups had significantly lower fracture resistance than the control group (P < 0.05). Neither the tested calcium silicate cements nor the bleaching procedures had a significant impact on fracture resistance values.

Effect of Laser-Activated Irrigation on the Push-Out Bond Strength of ProRoot Mineral Trioxide Aggregate and Biodentine in Furcal Perforations.

OBJECTIVE: The objective of the present study was to assess the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser-activated irrigation (LAI) of NaOCl on the push-out bond strength of furcal perforations repaired with ProRoot mineral trioxide aggregate (MTA) and Biodentine. BACKGROUND DATA: Several studies investigated the adhesion of calcium silicate-based cements after exposure to endodontic irrigants, while effect of LAI on bond strength remains to be elucidated. MATERIALS AND METHODS: Bur-cut furcal perforations with standard dimensions were created in 100 extracted human mandibular molars. Teeth were randomly distributed into two groups (n = 50/group) according to the repair material applied: (1) ProRoot MTA or (2) Biodentine. The specimens were further assigned into five subgroups according to the irrigation regimens used over the set materials: (a) distilled water with needle irrigation; (b) 5.25% NaOCl with needle irrigation; (c) distilled water with LAI; (d) 5.25% NaOCl with LAI; and (e) no irrigation (control). Bond strengths of the test materials were assessed by using push-out bond strength test. RESULTS: Biodentine showed significantly higher dislocation resistance than ProRoot MTA (p < 0.05). Laser activation of 5.25% NaOCl and distilled water did not significantly affect the push-out bond strength results (p > 0.05). CONCLUSIONS: Biodentine showed higher dislocation resistance than ProRoot MTA as a perforation repair material. Er,Cr:YSGG laser activation of irrigation aqueous solutions had no adverse effect on push-out bond strength of Biodentine and ProRoot MTA.

Effectiveness of pit and fissure sealants bonded with different adhesive systems: a prospective randomized controlled trial.

OBJECTIVES: To evaluate and compare the clinical retention of a resin-based fissure sealant placed with an intermediate layer of etch-and-rinse (ER) or self-etch (SE) adhesives. MATERIALS AND METHODS: Two hundred twenty-eight sealants were placed in 57 children with previously unsealed, caries-free permanent first molars, employing a split-mouth design. The teeth were randomized into four groups (n = 57 teeth/groups) according to the adhesive system placed under the tested sealant (Delton FS+; Dentsply). Group 1 (control): no bonding agent (conventional acid-etch sealant); group 2: prior enamel etch + ER adhesive (XP Bond; Dentsply); group 3: SE adhesive (Clearfil SE Bond; Kuraray) without prior etching; and group 4: prior enamel etch + SE adhesive (Clearfil SE Bond). Clinical assessments were performed according to modified USPHS criteria at 1, 3, 6, 12, 18, and 24 months. The data were analyzed statistically using Fisher's Exact test, the Kaplan-Meier analysis, and the Log-rank test. RESULTS: At 24 months, sealants bonded with XP Bond and Clearfil SE Bond with prior enamel etching showed similar retention rates (p > 0.05), and these rates were significantly better than the rates of the conventional sealant and Clearfil-SE groups (p < 0.05). There was no significant difference between the retention rates of the latter two groups (p > 0.05). The cumulative survival rates on palatal/buccal surfaces showed similar outcomes as with occlusal surfaces: XP Bond (94%), Clearfil SE Bond + acid-etch (94%), conventional sealant (52%), and Clearfil SE Bond only (37%). CONCLUSIONS: Application of the tested ER adhesive and the SE adhesive with enamel etching significantly improved the clinical retention of Delton-FS over the 24-month period. CLINICAL RELEVANCE: The use of a resin-based fissure sealant placed with ER or SE adhesive with prior acid-etching yielded better retention than the conventional sealant over the 24-month period.

Effect of Laser-Activated Irrigation with Ethylene Diaminetetraacetic Acid and Phytic Acid on the Removal of Calcium Hydroxide and Triple Antibiotic Paste from Root Dentin.

OBJECTIVE: This study assessed the efficacy of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser-activated irrigation (LAI) of ethylene diaminetetraacetic acid (EDTA) and phytic acid on the removal of calcium hydroxide (CH) and triple antibiotic paste (TAP) from root canals. BACKGROUND DATA: Although some studies investigated the efficacy of LAI of EDTA irrigation, no study has been conducted to investigate the efficacy of LAI of phytic acid in the removal of CH and TAP from root dentin. MATERIALS AND METHODS: Root canals of extracted maxillary incisors (n = 80) were instrumented using rotary files and thereafter were split longitudinally. Following preparation of a standardized groove in the apical region of one root half, the roots were randomly divided into two groups according to the intracanal medicaments placed into the grooves: (1) CH and (2) TAP. The roots were reassembled, and the specimens were further assigned into four groups (n = 10/group) defined by the final irrigation solution (EDTA and phytic acid) and irrigation technique (needle irrigation and LAI) used for removal of the medicaments. The data were analyzed statistically using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: For both EDTA and phytic acid, LAI was more efficient than needle irrigation in removing both CH and TAP (p < 0.05), but none of the tested techniques completely removed CH. Irrespective of the tested irrigation solutions and techniques, significantly less TAP remained in canals (p = 0.0001), with TAP being completely removed by LAI. Irrigation with phytic acid showed better removal efficacy than EDTA in the absence of statistical significance. CONCLUSIONS: Er,Cr:YSGG LAI of EDTA and phytic acid completely removed TAP and effectively reduced CH on root dentin.

Evaluation of goat milk as storage media to preserve viability of human periodontal ligament cells in vitro.

BACKGROUND AND AIM: The purpose of this study was to evaluate the effectiveness of goat milk as a storage media for maintenance of periodontal ligament (PDL) cell viability of avulsed teeth and compare it with commonly used and/or investigated storage media. MATERIALS AND METHODS: PDL cells were obtained from the root surface of healthy premolars and were cultured in Eagle's maintenance medium (EMM). Cell cultures were treated with the following storage media: tap water (negative control); EMM (positive control); Hank's balanced salt solution; ultra high temperature (UHT) long-shelf-life lactose-free cow milk; UHT long-shelf-life whole cow milk; UHT long-shelf-life skimmed cow milk; UHT long-shelf-life soy milk; UHT long-shelf-life goat milk, UHT long-shelf-life follow on milk with probiotic, 20% propolis, and egg white. Culture plates were incubated with experimental media at 20°C for 1, 3, 6, 12, and 24 h. PDL cell viability was assessed by tetrazolium salt-based colorimetric (MTT) assay at each test period. One-way anova was used to evaluate the effects of storage solutions at each time point, followed by post hoc Duncan's multiple comparison test (P = 0.05). A dendrogram was constructed to show the arrangement of hierarchical clustering. RESULTS: Goat milk displayed the highest capacity to maintain cell viability at all test intervals (P < 0.001). Between 3 and 24 h, milk with the probiotic showed the lowest time-dependent PDL cell viability among all test media (P < 0.001). Compared with all milks, HBSS performed significantly less effectively in maintaining PDL cell viability during the entire test period (P < 0.001). CONCLUSION: Based on PDL viability, goat milk can be recommended as a suitable storage medium for avulsed teeth.

Effect of ozone pretreatment on the microleakage of pit and fissure sealants.

OBJECTIVE: This study investigated the effect of ozone pretreatment on the microleakage and marginal integrity of pit and fissure sealants placed with or without a self-etch 6th generation adhesive. STUDY DESIGN: Freshly-extracted, human third molars were randomly assigned into two main groups (n = 48): Group A: Fissures were pretreated with ozone; Group B: Fissures were left untreated. The teeth were further randomly divided into two subgroups (n = 24/each) so that half of teeth were sealed with a conventional fissure sealant (Fissurit F, Voco, Germany), while the remaining half received the same sealant bonded with a self-etch adhesive (Clearfil Protect Bond, Kuraray, Japan). Following thermal cycling (1000X), the specimens were subjected to dye penetration within 0.5% basic fuchsin for 24h. The extent of dye penetration was measured by image analysis. Kruskal Wallis and Mann-Whitney U tests were used for statistical analysis of the data (p = 0.05). Two randomly-selected sections from each group were observed under SEM RESULTS: In all groups, ozone pretreatment significantly reduced the extent of microleakage (p < 0.001). SEM investigation demonstrated better adaptation of the sealants in ozone-pretreated groups. Clearfil Protect Bond did not improve the marginal seal of Fissurit F (p > 0.05). CONCLUSION: Ozone pretreatment favorably affected the marginal sealing ability of the tested fissure sealants.

Impact of similarity in chemical composition of light-polymerized resin composites on post-gel strains and interface integrity.

The post-gel strains of two light-polymerized resin composites having similar chemical composition, Filtek P60 and Filtek Z250, was assessed by strain-gauge analysis at the ex vivo level. The restoratives were tested in cavity factor 5 during light-polymerization and water-soaking for 24 h. Strain-gauge signals were digitalized by a data acquisition system and were displayed in a computer by corresponding software at a sample rate of 20 Hz. The strain data were used to compare post-gel strains, polymerization velocity, and total volumetric change of both materials. Evaluation of microleakage and scanning electron microscopy was also undertaken to elucidate effects of post-gel strains at the tooth-restorative interface. Microstrains of Filtek Z250 were lower than those of Filtek P60 and the differences between post-gel strains at several different time intervals were significant (P < 0.009). There was a correlation between polymerization velocity and total volumetric change. Microleakage evaluation and scanning electron microscopy did not reveal any signs of debonding at the interface for both materials. We conclude that the similarity in chemical composition of light-polymerized resin composites is not a determinant for post-gel strains. The tooth-restorative interface can withstand high post-gel strains arising from polymerization of resin composites.